Hydro presented the results of three studies developed in partnership with Brazilian Scientific, Technological and Innovation Institutions (ICTs, in Portuguese), focused on the recovery of bauxite residue, during the 39th International Committee for the Study of Bauxite, Alumina and Aluminum - ICSOBA, one of the main global events in the sector. The organizing committee selected researches with a focus on sustainable development and carbon footprint reduction. The edition was carried out virtually on the 22nd, 23rd and 24th of November. The three cases presented by Hydro and partners were aimed at developing innovative solutions for the sustainable use of bauxite residue in new products, applying the concepts of circular economy.
“This partnership between Hydro and scientific institutions is part of our sustainability strategy. We seek to be a pioneering and innovative reference in the aluminum and mining chain. The company's purpose is to create a more viable society, by developing natural resources into products and solutions in an innovative and efficient way. Based on our belief that sustainability can generate profitability, we are investing in advanced technologies and taking advantage of sustainable initiatives to make our operations a benchmark in safety, innovation, environmental protection and social responsibility”, says Marcelo Montini, Hydro's chemical consultant.
In partnership with the Federal University of Pará (UFPA), Hydro conducted research on the production of Portland cement using bauxite and washing residues, materials generated at Hydro Alunorte and Hydro Paragominas, respectively, with a view to reducing emissions of CO2. The study concluded that there is a strong potential for cement production from the use of bauxite residues. To deepen the research, new studies will be carried out to verify the long-term durability and stability of the product.
The article "Citric, ascorbic and acetic acids for neutralizing the pH of bauxite residue and its effects on the sodalite phase", in partnership with the SENAI Institute of Innovation in Mineral Technologies (ISI-TM), evaluated the pre-treatment with bauxite residue’s organic acids, from the filter-press process, with the purpose of improving its physicochemical and mineralogical characteristics. The results showed the potential of citric acid as a pre-treatment option for bauxite residue, which could facilitate its greater use in new products, for example, in the areas of steel, civil construction and agriculture.
Another research focused on the use of bauxite residue was a partnership between Hydro and the University of São Paulo (USP). The researchers presented the results of the study on the production of concrete blocks for paving with bauxite residue. Aiming at reducing emissions, the group monitored performance and durability for 6 months at the Alunorte plant. Mechanical properties, strength and water absorption were evaluated. Concrete blocks produced with bauxite residue presented the same resistance performance as blocks manufactured without the presence of residue.
The ICSOBA conference takes place annually and highlights the main players in the bauxite, bauxite residue, alumina and aluminum market. Due to covid-19's pandemic protection measures, this year the event was held remotely. More than 100 works were presented.